基于信息分配和扩散理论的东北地区干旱脆弱性特征分析

基于信息分配和扩散理论, 结合标准化降水指数和东北三省(黑龙江、吉林、辽宁)旱灾灾损指数, 综合考虑了气象因子与社会因子, 分析了我国东北三省1971–2012年的干旱脆弱性特征, 并进一步计算了我国东北三省的干旱风险. 使用信息分配方法估计干旱强度概率分布, 采用二维正态信息扩散方法构造了干旱强度与旱灾灾损的脆弱性关系, 将干旱强度的概率分布与脆弱性折线相乘求和(离散分布)或积分(连续分布)即可得到多年平均风险. 研究表明, 针对灾损的小样本事件引入信息分配和扩散方法对小样本数据进行分析, 获取的干旱强度概率分布比简单直方图法所得更加平滑, 而以事件为因、灾损为果得到干旱强度-旱灾灾损的脆弱性关系, 物理意义明确, 所得脆弱性关系折线也比较符合实际情况, 并且不同样本长度所得结果相近, 对样本长度不敏感, 较好地克服了小样本分析的不稳定性. 关键词： 信息分配和扩散理论 标准化降水指数 脆弱性 风险

Analysis of the drought vulnerability characteristics in Northeast China based on the theory of information distribution and diffusion

The drought vulnerability characteristics from 1971 to 2012 in Northeast China are analysed and the risk in Northeast China is calculated based on the theory of information distribution and diffusion, combining with the standardized precipitation index (SPI) and the drought damage index (DDI) in Northeast China, with considering the meteorological factors and social factors. The probability density function (PDF) of DSI is estimated by using the method of information distribution. The vulnerability of the relationship between DSI and DDI is constructed by using the method of two-dimensional normal information diffusion. Then the average risk can be obtained by calculating the sum (discrete distribution) or integral (continuous distribution) of the product of the PDF of DSI and the vulnerability curve. The results show that the introduction of information distribution and diffusion method to analyze the problem of vulnerability for the situation of small sample could render the PDF of DSI smoother. What is more, the vulnerability of the relationship between DSI and DDI through the DSI to obtain the DDI has clearer physical meaning. Therefore the results could be realistic. More significantly, similar results can be obtained with different simple lengths, which means that the method is insensitive to the simple length and it can well overcome the instability of analysis of the small sample.
Keywords： information distribution and diffusion standardized precipitation index vulnerability risk